The invention relates to circuit means for providing reticle brightness in an image intensifier in which the reticle brightness is commensurate with an object image input source brightness.
Specifically, the invention comprises a reticle brightness control circuit having two common inputs thereto that control an output which regulates the voltage across a reticle LED. Both inputs to the reticle brightness control circuit are controlled by a screen current sensing circuit, one directly and the other indirectly through an automatic brightness control circuit. When the screen current increases through the automatic brightness control circuit, the indirect control limits the output voltage of the MCP OSC circuit inversely with the variations of the screen current wherein the output voltage of the MCP OSC circuit is fed back to the input of the reticle brightness control circuit for proportionately applying current through the reticle LED according to the amount of screen current.